5 Signs Of A Failing Canister Purge Valve
The canister purge valve is a vital part of the Evaporative Emission Control System (EVAP). The purpose of the EVAP system is to prevent large amounts of fuel vapors from escaping into the atmosphere and from getting into your vehicle. In particular, the canister purge valve is an emissions control component that allows the engine intake vacuum to take the exact amount of fuel vapors from the EVA canister into the engine intake manifold. In newer model vehicles the purge valve is electrically operated solenoid controlled by the engine computer. When your engine is off, the valve is closed. Once your engine is up and running, the computer continuously and moderately opens the purge valve. This action allows fuel vapor to move from the charcoal canister to burn in the engine.
Like many automotive parts, dust and dirt can clog the canister. The purge valve can even crack from harsh conditions in the environment. If the purge valve fails, it can cause problems for the EVAP system which will negatively affect your car’s emission output level.
Below are the top 5 symptoms of a bad vapor canister purge valve.
1. Check Engine Light
The most common problem with the purge valve is when it sticks or does not close fully. This may cause the "Check Engine" warning light to come on. Common error codes include P0441 and P0446, as well as other EVAP codes. If your check engine light turns on, take your car to a mechanic to diagnose the problem immediately.
2. Rough Idle
If your canister purge valve is not opening correctly, your vehicle will not run smoothly. It will run at an inconsistent rate as you’re driving, especially at low speeds. Usually, a damaged purge valve can cause a vacuum leak which can lead to rough idle.
3. Hard Starting Car
A stuck-open purge valve can cause difficulty starting. A vacuum leak because of a bad vapor canister purge valve, can lead to problems starting your vehicle. This will cause outside air to enter your engine and interfere with the overall internal combustion process. If you have unmetered air mixing with fuel in the cylinder chamber, then it will cause engine problems. The most obvious issue will be an engine that does not start.
4. Bad Engine Performance
If the canister purge valve is stuck open, you will experience a weaker performance from your engine. It means, even if you press down on your gas pedal, your engine will not be able to generate enough power to accelerate, instead of running faster, it will move slower.
5. The vehicle fails the emissions test
The vapor canister purge valve is responsible for redirecting fuel vapors back into the engine. This is preventing toxic hydrocarbons from being emitted from your tailpipe. If you have a failing purge valve, then it wouldn’t be able to redirect those fuel vapors and prevent them from escaping your vehicle. More than that, your car will fail the emission test if this happens. That’s why you should go to your mechanic and let them check your purge valve. If it’s worn or damaged, replace it with a new one. Only after replacing it, you will be able to pass the emissions test.